The Michael addition reaction is well known as a curing mechanism for decorative and protective coatings. Typically, the reaction is catalyzed by strong base such as primary or secondary amines that cause yellowing and can also reduce the hydrolytic stability of coatings formulated with polymers that have linkages susceptible to hydrolysis such as polyesters.
Tertiary phosphines are known to catalyze Michael addition reactions. However, they are used under conditions where curing is through exposure to UV light or under conditions with extended pot lives and/or curing at elevated temperatures. See for example U.S. Pat. No. 3,729,484; 5,084,536; 5,496,896 and 2006/0094804.
For certain applications is would be desirable to catalyze Michael addition reactions with tertiary phosphines where cure occurs rapidly, that is within a few seconds after a coating containing the Michael addition reactants are applied to a substrate. For example, in the coating of large vertically disposed substrates such as bridges or buildings it would be desirable to apply the coating composition and have it cure immediately at ambient temperature.